Automated food processing machines have become prevalent in the art for creating food xe2x80x9cset-upsxe2x80x9d for future use, such as sandwich making, and for creating stacks of food products for storage and shipping. Certain foods however, such as cooked bacon, are difficult to stack because they are slippery. Many foods contain an amount of grease necessitating the use of a substrate which is resistant to grease permeation, such as waxed or plasticized paper. When the food on the substrate is decelerated from a conveyor in order to stack it for shipping or additional processing, the foods have a tendency to slide along the substrate surface, causing spillage and uneven stacking.
In one prior known automatic in-line food preparation machine, disclosed in U.S. Pat. No. 5,768,857, of which the present inventor is a co-inventor, slices or pieces of food product are placed on a conveyor system and transferred onto an approved substrate, such as paper or polyethylene, introduced onto the conveyor beneath the food product as the food product travels along the conveyor path. Thereafter, the food product-laden substrate is transferred to a stacker to produce a neat and efficient stack of the food products separated by the substrates. However, for slippery foods, the deceleration required at the stacker causes the food products to move on or even slide off the substrate, requiring the equipment to run at reduced speeds, well below the capacity of the equipment.
In one known application, cooked bacon was layered or stacked on a 9-inch by 14-inch paper substrate. The deceleration for transferring each bacon-laden substrate from the conveyor to the stacker necessitates a reduced conveyor speed so that only approximately 20-22 units per minute of cooked bacon laden substrates can be stacked without causing the bacon to slide off the substrate upon entry to the stacker.
The inherent limitations for the above described systems inhibit the overall efficiency of stacking operations. Currently, there is a need for an efficient and cost-effective stacking mechanism for slippery products, such as cooked bacon, which are placed on substrates and stacked.
The present invention provides an anti-inertia stacker for stacking products and which is especially useful for stacking products located on a substrate which are prone to dislodgment on or from a substrate during processing movement. The anti-inertia stacker comprises a traveling pallet which is mounted for movement along a defined path, the pallet including a plurality of independently rotatable parallel rollers connected to a support. The rollers are independently driveable in a direction opposite to a direction of travel of the traveling pallet. A drive member is mounted for movement by a control actuator into and out of contact with the traveling pallet in the stacking area. A sensor is located along the path of the traveling pallet for sensing the product or a product laden substrate and signaling a controller which activates the control actuator to move the drive member into engagement with the rollers to drive one or more of the rollers.
In a further improvement of the invention, a stacker sensor is provided which detects a position of a stacked product or product laden substrate and signals stack position data to the controller. The controller compares the stack position data to a preferred stack position and adjusts a timing of the activation of the control actuator so that the timing of the drive member engaging the rollers is advanced or retarded to attain a desired stack position.
Preferably, the rollers include non-intermeshing pinion gears and the drive member comprises a rack which can be brought into and out of engagement with one or more of the pinion gears of the rollers to drive one or more of the rollers
Alternatively, the rollers can be acted upon by a moving belt that engages the rollers and is initially moving at the same speed as the traveling pallet. The direction and/or speed of the moving belt is then controlled to provide a gradual or more rapid deceleration and stacking of the products or product laden substrates.
In another aspect, the invention provides an anti-inertia bacon stacker which receives substrates laden with strips of cooked bacon from at least two in-feed lanes. Sensors are located along the at least two in-feed lanes to determine if a product-laden substrate is present, and signal the controller to actuate one or more diverters so that the product laden substrate from all of the in-feed lines is directed to a single stacker feed line. The controller also can adjust the speed and/or stop the in-feed lines to ensure that a single product-laden substrate is fed to the stacker at one time.
In another aspect, the invention provides an anti-inertia stacker having a traveling pallet as described above with two spaced-apart drive members. The drive members are moveable from a first, active position which contacts the traveling pallet to a second, non-active position. Two stacking pallets or receiving areas are provided to accept items to be stacked from the conveying surface to a top of a respective stack.